A user apparatus in a mobile communications system is disclosed. The user apparatus includes a unit which receives, from a base station apparatus, a downlink control signal including information for allocating a radio resource; a unit which determines, depending on a channel status, a pre-encoding matrix indicator (PMI) which indicates a pre-encoding matrix to be applied to multiple antennas of the base station apparatus; and a unit which transmits, to the base station apparatus, an uplink signal including the PMI, wherein, if the radio resource is allocated to a physical uplink shared channel of the user apparatus, the PMI is transmitted using a part of the radio resource, and, wherein, if the radio resource is not allocated to the physical uplink shared channel of the user apparatus, the PMI is transmitted in a physical uplink control channel which is allocated, in a fixed manner, to the user apparatus.